1)Svejina Dimitrova, 2)Eng. Zornitsa Zaharieva
1)Astronomical Observatory and Planetarium
Varna, Bulgaria, 2)CERN, Geneva, Switzerland

1)Svejina Dimitrova, 2)Eng. Zornitsa Zaharieva
1)Astronomical Observatory and Planetarium
Varna, Bulgaria, 2)CERN, Geneva, Switzerland